getRelativeLocaleUrl returns an empty string

[mversic]

Astro Info

Astro                    v5.1.7
Node                     v23.5.0
System                   macOS (arm64)
Package Manager          pnpm
Output                   static
Adapter                  none
Integrations

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

getRelativeLocaleUrl('en') (where en is the defaultLocale) returns an empty string. This is a problem because href cannot be empty as for example in a link tag <a href={getRelativeLocaleUrl('en')}>. This would give <a href=""> when I expected <a href="/">

This is my astro config:

export default defineConfig({
  trailingSlash: 'never',
  i18n: {
    locales: ['en', 'fr'],
    defaultLocale: 'en',
  },
});

What's the expected result?

getRelativeLocaleUrl('en') returns "/" because an empty string is not a valid relative URL as demonstrated with the <a> tag

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-bvnpwdin-tdbvtznt

Participation

• I am willing to submit a pull request for this issue.

[mversic]

also make sure that getAbsoluteLocaleUrl('en') doesn't return empty string when site is not defined in the config